#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>

int main()
{
	int a, b, c, digit;
	scanf("%d%d%d", &a, &b, &c);
	digit = (a * 20 + b * 30 + c * 50) / 100;
	printf("%d", digit);
	return 0;
}